Heart disease is often viewed as a health problem that affects mostly men. But nearly half the heart attack deaths in 2010 were in women.
While rates of heart disease remain high—there were nearly a million heart attacks in 2010 —they have been on a decline over the past 40 years, partly due to better medical care. An increased awareness of the relationship between diet and heart disease has had an impact, too. For example, more people than ever have a good understanding of the dietary components that raise or lower blood cholesterol levels. Many may not realize, however, that factors other than blood cholesterol affect heart disease risk, too. For example, recent research has shown that eating soyfoods may benefit heart health even in people whose cholesterol levels are normal.
Among commonly-consumed foods, soybeans are a unique source of isoflavones, compounds that are a type of plant estrogen or phytoestrogen. Isoflavones have been extensively studied for potential benefits in a variety of areas, including their impact on the health of the arteries. Recently, scientists from the Division of Cardiovascular Medicine, Yao Municipal Hospital, in Japan, examined the effects of soybean isoflavones on the arteries of pre and postmenopausal women.
For two months, the subjects in the study consumed about 50 milligrams of isoflavones every day, or the amount provided by approximately two servings of soyfoods. The researchers measured the stiffness of their arteries and the ability of arteries to dilate before and after consuming isoflavones. Stiffer arteries and arteries that are less able to dilate are considered signs of early atherosclerosis and suggestive of an increased risk for a heart attack.
Consuming isoflavones significantly improved the ability of the arteries to dilate in both pre- and postmenopausal women as long as they were non-smokers. Isoflavones decreased the stiffness of the arteries in premenopausal women whether they smoked or not, but didn’t have an effect in older women.
Soyfoods are a smart choice for reducing risk of heart disease for a number of reasons. They’re low in saturated fat and they provide a type of protein that reduces blood cholesterol levels. The evidence that soy isoflavones have unique benefits for the health of the arteries in both older and younger women is one more reason to include soy in your heart healthy diet.
Hoshida S, Miki T, Nakagawa T, Shinoda Y, Inoshiro N, Terada K, Adachi T. Different effects of isoflavones on vascular function in premenopausal and postmenopausal smokers and nonsmokers: NYMPH study. Heart Vessels 2011.